In the past year, it seemed as if reinfections with the corona virus were rare. Yes, they have happened, but the vast majority of people who have already had COVID would likely not contract the virus again anytime soon.

However, recent data suggest that reinfections are becoming more common, particularly as new variants become established. The New York City Health Department recently released one report showing that just over 4% of all COVID infections in the state have been reinfections – and that nearly 87% of them have occurred since December 2021. Washington reported that 45,312 people had reported reinfection since September 2021 – 2.3% of them were hospitalized and 0.2% died.

The increase in reinfections is likely driven by two factors: first, that newer variants can evade the antibody response and become reinfected, and second, that we now document reinfections more rigorously and get a more accurate picture of how common they are.

It is well known that coronaviruses keep infecting people. In fact, it is widely believed that the common cold coronaviruses that are circulating today (and often reinfecting people) originated from previous coronavirus epidemics. Many infectious disease doctors suspect that, like these strains, we may be susceptible to reinfection, but that the symptoms will become progressively milder over time.

“Hopefully as we get more immunity, our T cells become more diverse and broadened, our second reinfection won’t feel as bad as the first infection,” he said Monica Gandhian infectious disease specialist at the University of California, San Francisco.

We now know that antibodies, which are primarily designed to prevent infection, are starting to decline a few months after vaccination or infection. Additionally, as the coronavirus mutated, it became a little less detectable to the immune system.

Because of this, variants are able to evade the immune system’s first line of defense and reinfect us Julie ParsonnetEpidemiologist and Professor of Infectious Diseases at Stanford University School of Medicine.

“With omicron, we’re seeing a lot of cases in previously infected people, even if they’ve also been vaccinated,” Parsonnet said.

Pablo Penaloza-MacMasteran assistant professor of microbiology-immunology at Northwestern University Feinberg School of Medicine, said people who recently recovered from an infection or had a booster could be susceptible to reinfection in about six months.

Parsonnet noted that she heard from at least one patient who was fully vaccinated and double-boostered and contracted Omicron six weeks after their previous infection.

A recently to learn from Denmark thought so very Rarely, reinfections with omicron subvariants can occur in as little as 20 days. Of the 1.8 million infections registered between November 2021 and February 2022, 1,739 reinfections were detected within 60 days.

That doesn’t mean that a few months into recovery there’s a good chance you’ll get COVID again. In fact, a form study recently found that infections were 90% less common in people who already had COVID than in people who had never been infected. Getting infected on top of the vaccine really boosts your health antibody levels, and that should keep most people well protected from infection for at least four months, Gandhi said.

It’s not an exact science to determine who is more likely to be reinfected – some people are better protected and less likely to be reinfected, depending on factors like theirs Age, genetics and underlying health. The rate of reinfection also depends on the variant — the type of mutations the virus has picked up — and the viral load someone is exposed to, according to Penaloza-MacMaster.

The bulk of the evidence suggests that COVID reinfections are generally less severe than the initial infection. In Danish to learnnearly everyone who was re-infected with BA.2 after previously having BA.1 had mild symptoms for a few days and a significantly lower viral load the second time around — even those who were unvaccinated.

Even if our immune system weakens over time, the components keep us from doing so safe from illness and severe consequences remain robust and long-lasting (even if deal with new variants).

“Reinfections, particularly in vaccinated individuals, are typically milder than primary infection because an arsenal of memory T cells and B cells is already present.” said Penaloza-MacMaster.

research suggests that reinfections and boosters enhance the T cell response. “Basically, as you would expect, reinfection protects you even more from serious consequences,” Gandhi said. Of course, booster shots are the safest – you don’t want to intentionally reinfect yourself.

According to Penaloza-MacMaster, the severity of a person’s reinfection is also affected by the variant they contract, the dose of virus they are exposed to, and whether they have underlying health conditions that put them at risk. But often it can be unpredictable.

One of the key questions epidemiologists will pursue is how reinfections contribute to a long COVID.

We know COVID affects many organs including the brain, lungs and heart. Inflammation, which helps clear infected cells from the body, is a normal part of the body’s response to infection. When the body kills virally infected cells, it also destroys our own healthy cells.

“EEliminating a virus comes with a significant amount of “collateral damage,” which is one of the main reasons why long-term inflammation — that occurs with protracted infections — is harmful,” Penaloza-MacMaster said.

if and hCurrent reinfections contribute to a long COVID and possible damage to our organs is unclear. research has found that vaccination reduces the risk of a long COVID in people with a breakthrough infection, Gandhi said. And while the vast majority of people who contract SARS-CoV-2 recover well with no long-term consequences, it is not yet known if this will continue to be the case after multiple infections.

“We don’t know the answer to that question, particularly because as variants change and our immune systems respond differently, the effects on the body change,” Parsonnet said.

Experts are still learning about COVID-19. The information in this story is known or available at the time of publication, but guidance is subject to change as scientists learn more about the virus. Please check the Centers for Disease Control and Prevention for the most up-to-date recommendations.